Forward arrow worked well for me (same browser + OS) - though occasionally slow/janky. The presentation's creator mentions that it worked best on Firefox, I think.
It doesn't work at all on FF3.6.11/WinXP
It says Firefox 4 in the presentation
oh ok, thanks! I wouldn't know because it never went further than page 1 :)
Works fine for me on FF 3.6.12
Pretty strange, no luck on 3.6.12 as well.
It was really jerky and slow in Chrome 9 on OS X 10.6.4.